maprowseq.java

java web 开发,Java Xml 编程指南书籍源码

package MyNa.xml;

import java.util.*;
import java.io.*;
import MyNa.utils.*;


public class MapRowSeq extends RowSeq {
  RowSeq innerRows;

  String fieldName; int fieldNum; String val;
  // used in most common case, in which a field
  // is set to be a particular value. May be
  // used for other purposes with mapFunction
  // overridden.

public MapRowSeq(RowSeq re)throws Exception{
  super();
  innerRows=re; shallowClone(re);
  fieldName=null; fieldNum=-1; val=null;
}
public MapRowSeq(String field,String val,RowSeq re)
    throws Exception{
  super(); 
  innerRows=re; shallowClone(re);
  fieldName=field; this.val=val;
  if(theColumnLabels!=null)
   for(int i=0;i<theColumnLabels.length;i++)
     if(theColumnLabels[i].equals(field))
       {fieldNum=i; return;}
}
  
public void mapFunction(){ // applied to each Env.
  if(fieldNum>=0)theColumnValues[fieldNum]=val;
  theEnv.put(fieldName,val);
}
public boolean next(){
  if(!innerRows.next())return false;
  mapFunction();
  return true;
}

} // end MapRowEnum